JP2001191942A - Steering device for agricultural work machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly conduct the steering operation of an agricultural work machine having a pair of right and left crawler type travel devices. SOLUTION: The agricultural work machine has a pair of right and left crawler type travel devices, and a plurality of operation areas are formed in the operation regions from the neutral position n to the right and left turning directions of a single steering operation tool 42 so that the turning function is increased as separated further from the neutral position n. This steering device for the agricultural work machine has a variable resistor VR as an operation area adjusting means changing and adjusting the boundary position of a plurality of operation areas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering device for an agricultural machine having a pair of right and left crawler type traveling devices.

[0002]

2. Description of the Related Art As the steering device, for example, as disclosed in Japanese Patent Application Laid-Open No. 7-47973, a pair of left and right crawler type traveling devices are each provided with a side clutch, and a side clutch is provided. A slow turning drive means for driving the disengaged one of the traveling devices in the same direction as the operation direction of the other traveling device in which the side clutch is not disengaged, and at a speed lower than the operating speed; A braking mechanism as a rapid turning drive means for braking the traveling device, and when the steering operation tool is operated in a first operation area deviated to one of left and right from the neutral position, a side clutch of one traveling device is disengaged, When operated in the subsequent second operation area, the traveling device with the side clutch disengaged is decelerated by the gentle turning drive means, and further operated in the third operation area. Then, it is proposed that the steering operating tool and the side clutch, the gentle turning drive means, and the braking means are linked so that the traveling device with the side clutch disengaged is braked by the braking mechanism. I have.

[0003]

The steering device described above is effective in performing a smooth turning of the vehicle body, as the turning amount of the steering operation tool increases, the turning function thereof gradually increases. However, the relationship between the turning function and the operation area has not yet been sufficiently considered. That is, in an agricultural work machine such as a combine machine, there are two types of machine steering during work traveling: steering for following the crop line and steering for largely changing the direction of the body at the ridge.

[0004] In the steering for causing the body to follow the crop line, carelessly turning the machine in large size may damage the crop or cause crop loss, and will not come off the crop line. It is necessary to pay attention to the steering operation. Also, in the steering to change the direction of the aircraft greatly at the ridge,
If the steering of the aircraft is slow, the turning space becomes large, and it is necessary to quickly make a small turn.

[0005] In addition, the degree of steering varies depending on differences in the hardness of the field, the moving speed of the fuselage, the skill of the pilot and the habit of the pilot, and the like. Because the operation area of the tool was decided uniformly,
Usability was not always good depending on the driving conditions.

The present invention has been made in view of such a situation, and it is an object of the present invention to provide a steering apparatus which can easily perform a steering operation required for an agricultural work machine according to various conditions. Its primary purpose.

[0007]

Means for Solving the Problems [Structure, operation and effect of the invention according to claim 1]

(Structure) The steering device for an agricultural work machine according to the first aspect of the present invention includes a pair of left and right crawler-type traveling devices, and each operation area from a neutral position of a single steering operation tool in a left-right turning direction. Further, in a steering device for an agricultural work machine having a plurality of operation areas, the boundary position of the plurality of operation areas can be changed and adjusted so that the turning function becomes higher as the distance from the neutral position increases. And

(Operation) According to the above configuration, during work traveling in a field, a loose body steering is started by operating the steering operation tool to an operation range close to the neutral position,
It is suitable for performing normal steering to follow a crop line. In addition, when a small turn is required, such as when changing the direction of the aircraft at the edge of a ridge, the steerable operation can be reliably performed by operating the steering operation tool to an operation area away from the neutral position.

[0010] Here, by changing and adjusting the boundary positions of the plurality of operation areas allocated to the operation area of the steering operation tool, it is possible to obtain various types of steering modes.
For example, by adjusting the boundary position between the operation range of the loose turning characteristic and the operation range of the tight turning characteristic so as to be far from the neutral position, and widening the operation range of the loose turning characteristic, it is easy to perform a loose body turning as a whole. Conversely, if the boundary position is adjusted so as to approach the neutral position and the operation range of the tight turning characteristic is widened, it becomes easy to perform a tight body turning as a whole.

(Effects) Therefore, according to the first aspect of the present invention, by appropriately setting the area of the operation area, the body steering during work traveling is appropriately performed without excessive steering. In addition to the above, it is possible to accurately and easily perform a small turning such as a direction change at a ridge or a direction change on a road, thereby improving the steering operability as an agricultural work machine.

[Structure, operation and effect of the invention according to claim 2]

(Structure) In the steering apparatus for an agricultural working machine according to the second aspect of the present invention, in the invention according to the first aspect, the plurality of operation areas are a first operation area, a second operation area, and a third operation area. The first operation area is an operation area in which one of side clutches provided in each of the transmission systems of the left and right traveling devices is disengaged to perform gentle turning by one drive, and the second operation area is provided. The region is an operation region in which one traveling device with the side clutch disengaged is decelerated and driven in the same direction as the other traveling device without the side clutch disengaged to perform a gentle turning by both driving. The operation range is set to be an operation range in which one of the traveling devices with the side clutch disengaged is braked to make a sharp turn.

(Operation) According to the above configuration, when the steering operation tool is operated from the neutral position to the first operation area deviated to one side in the left-right turning direction, the side clutch of one of the traveling devices is disengaged, and the traveling device becomes free. Slow body turning is performed by driving only the other traveling device in which the side clutch is not disengaged. Further, when the vehicle is operated in the subsequent second operation range, the aircraft is driven for gentle turning to the side where the side clutch is disengaged, and the aircraft is gently and reliably steered by the speed difference between the driven left and right traveling devices. I do. Further, when the operation is performed to the third operation range, the braking of one of the traveling devices with the side clutch disengaged is stopped, and the aircraft body can be surely made a small turn by driving only the other traveling device without the side clutch disengaged.

Further, by changing and adjusting the boundary position between the first operation region and the second operation region or the boundary position between the second operation region and the third operation region, the operation region for gentle turning can be obtained. A large operation mode and an operation mode with a large operation area for a tight turn can be obtained.

(Effects) Therefore, according to the second aspect of the invention, a gentle turning state by one drive, a reliable gentle turning state by both drives having a speed difference, and a sharp turning state by one drive and one braking, It is possible to set and operate various operation area ratios, and it is possible to appropriately operate the aircraft in an operation mode suitable for the traveling state.

[Structure, operation and effect of the invention according to claim 3]

(Structure) According to a third aspect of the present invention, in the steering apparatus for an agricultural work machine according to the first or second aspect of the present invention, the operation range adjusting means is manually and arbitrarily adjusted.

(Operation / Effect) According to the above configuration, the allocation of the plurality of operation areas can be arbitrarily changed and adjusted in accordance with the driving conditions, the skill of the operator, and the like, and the operability is excellent in usability. It will be.

[Structure, operation and effect of the invention according to claim 4]

(Structure) According to a fourth aspect of the present invention, in the steering apparatus for an agricultural work machine according to any one of the first to third aspects, the operation range adjusting means may include an operating speed of the steering operating tool. The automatic adjustment operation is performed based on the detection.

(Operation) According to the above configuration, when the operation speed of the steering operation tool is low, it is considered that a gentle body steering is going to be performed, and the boundary position is automatically set so as to widen the operation range of the gentle turning characteristic. Even if the steering operation tool is slightly enlarged, steering with a gentle turning characteristic is executed. Also, when the operating speed of the steering operation tool is high, it is considered that the user is about to perform a sudden aircraft steering,
The boundary position is automatically changed so as to widen the operation range of the tight turning characteristic, and the steering with the tight turning characteristic is executed without greatly operating the steering operation tool.

(Effects) Therefore, according to the fourth aspect of the present invention, it is possible to perform the operation without changing the boundary position of the operation area one by one.
A steering mode suitable for the driver's consciousness is automatically displayed,
Excellent operability.

[Structure, operation and effect of the invention according to claim 5]

(Structure) In the steering apparatus for an agricultural work machine according to the invention according to claim 5, in the invention according to any one of claims 1 to 4, an operation range closest to neutral to the grip portion of the steering operation tool. And a finger operating tool that provides a turning state with the turning characteristics of the present invention.

(Operation) According to the above configuration, only by operating the finger operating tool provided on the grip portion of the steering operating tool,
Since the steering state has a gentle turning characteristic, when the vehicle does not require tight steering, such as when following a row of crops in a field, the aircraft can be maneuvered with only a light finger operation. When it is necessary to make a large turn of the aircraft, for example, it is also possible to perform steering of the aircraft with desired characteristics using a steering operation tool by hand.

(Effect) Therefore, according to the fifth aspect of the present invention, the steering operation means can be selected according to the running conditions, which is effective in improving the operability.

[0028]

FIG. 1 is a right side view of a combine as an example of an agricultural working machine to which the present invention is applied.
This combine is a pair of left and right crawler-type traveling devices 1
A cutting pre-processing unit 3 is connected to the front of a traveling body 2 having L and 1R so as to be movable up and down, and a threshing device 4, a grain tank 5, an engine 6, a control unit 7, and the like are mounted on the body. It has a structure.

Hereinafter, the transmission structure of the traveling devices 1L and 1R will be described with reference to FIGS. 2, 3, and 4. The description in the left-right direction in the description is based on the left-right direction of the body, and The relationship is opposite to the left-right direction in these figures.

The power of the engine 6 is controlled by a hydrostatic continuously variable transmission (H) as a main transmission capable of switching between forward and reverse.
ST) 8, and the shift output is transmitted to the transmission case 9. The power input to the transmission case 9 is transmitted to the first shaft 10 via the gears G1 and G2, and then to the auxiliary transmission mechanism 11 via the gears G3 and G4. Further, of the power taken out of the case from the first shaft 10, only the forward rotation power is transmitted to the pre-cutting unit 3 via the one-way clutch OC. The hydrostatic stepless transmission 8 is operated by a main transmission lever 29 provided in the control unit 7.

The sub-transmission mechanism 11 performs three-stage gear shifting in a constant mesh system.
The small-diameter gear G5, the medium-diameter gear G6, and the large-diameter gear G7, which are loosely mounted on the second shaft 12, are always engaged with the gears G8, G9, G10 fixed to the third shaft 13, respectively, and are disposed on the second shaft 12.
By shifting the two shift sleeves S1 and S2, 3
The second shaft 12 is formed by using any one of the pair of normally meshing gear pairs.
To the third shaft 13.

That is, as shown in FIGS. 5 and 6, the shift sleeves S1 and S2 are provided with a pair of shift forks provided on a shifter 15 which slides along a support shaft 14 horizontally supported in a transmission case. The shift sleeves S1 and S2 are simultaneously engaged in the same direction with the sliding displacement of the shifter 15, respectively. An operation arm 16a that engages with the shifter 15 is provided at the tip of a transmission operation shaft 16 that is mounted in the transmission case 9 back and forth. By rotating the speed change operation shaft 16, the shifter 15 is rotated.
Is slid left and right.

Here, the shift sleeve S1 is directly spline-engaged with the second shaft 12 throughout the shift range, whereas the shift sleeve S2 is connected to the boss portion of the gear G6 and the second shaft 12. The shift can be performed over the spline collar 17 fitted outside the spline and the boss portion of the gear G7, and three-speed shifting is performed as follows.

When the shifter 15 is in the low-speed "L" position, as shown in FIG.
And the shift sleeve S2 is externally supported only by the boss of the gear G6, and the power of the second shaft 12 is transmitted by the shift sleeve S1, the gear G5, It is transmitted to the third shaft 13 at a low speed via G8.

When the shifter 15 is at the medium speed "M" position, as shown in FIG. 8, the shift sleeve S1 is supported only by the second shaft 12, and
2 is in a state of being externally engaged with the boss portion of the gear G6 over the spline collar 17, and the power of the second shaft 12 is supplied by the spline collar 17, the shift sleeve S2, the gear G6,
It is transmitted to the third shaft 13 via G9 at a medium speed.

When the shifter 15 is in the neutral "N" position, as shown in FIG. 9, the shift sleeve S1 is supported only by the second shaft 12, and
2 is externally supported only by the spline collar 17, and the power transmission from the second shaft 12 to the third shaft 13 is shut off.

When the shifter 15 is at the high speed "H" position, as shown in FIG. 10, the shift sleeve S1 is supported only by the second shaft 12, and the shift sleeve S2 is in contact with the boss of the gear G7. It is in a state of being fitted over the spline collar 17 and the power of the second shaft 12 is
Spline collar 17, shift sleeve S2, gear G7
, G10 to the third shaft 13 at high speed.

Note that, as shown in FIG.
5 is a low speed “L” which is a harvesting speed of lodging culm, a medium speed “M” which is a standard harvesting speed, a neutral “N” which is a standard harvesting speed, and a high speed “which is a moving speed” by the ball detent 18. H ".

The power transmitted to the third shaft 13 as described above is transmitted to the center gear G11 of the fourth shaft 19 via the central gear G9, and then to the left and right side clutches 2.
0L, 20R, axle gears 21L, 21R, and axles 22L, 22R are transmitted to left and right traveling devices 1L, 1R.

As shown in FIG. 4, the side clutch 2
0L and 20R shift the side clutch gears 23L and 23R, which are loosely fitted on the fourth shaft 19 and are always engaged with the axle gears 21L and 21R, to shift the center gear G11.
The power transmission from the center gear G11 to the axles 22L, 22R is interrupted by disengaging from the lateral side of the center internal teeth of the gears. The means for shifting the side clutch gears 23L, 23R is as follows. It is configured as follows.

The fourth shaft 19 has a large diameter stepped shaft at the center and a side clutch gear 23.
L, 23R have a stepped inner diameter that fits over the large diameter portion and the small diameter portion of the fourth shaft 19, and are normally slid toward the center gear G11 by the spring 24, It is held in the clutch engaged position. And the fourth
By supplying the pressure oil through oil passages a and b formed in the shaft 19, the side clutch gears 23L and 23R
Are shifted to the clutch disengagement position against the spring 24. Also, the side clutch gear 23L,
When the gear 23R is shifted to the clutch disengaged position disengaged from the center gear G11, the oil passages a and b for supplying hydraulic oil are
It is configured to communicate with an oil passage d formed inside the fourth shaft 19.

The side clutch gears 23L, 2L
The 3R is further shifted beyond the clutch disengagement position at which the engagement with the center gear G11 is disengaged, so that the steering side gears 25L, 2 loosely fitted to both end portions of the fourth shaft 19 are mounted.
It can be occlusally connected to 5R from the side. The steering side gears 25L, 25R are engaged with the gears 27L, 27R fixed to both ends of the fifth shaft 26, and the gear G13 loosely fitted on the fifth shaft 26 is connected to the center gear G11. The gear G12 is engaged with a small-diameter gear G12 connected to the side and is decelerated.

Between the gear G13 and the fifth shaft 26, there is provided a multi-plate clutch C which performs gentle turning. In this clutch C, the piston 32 is normally retracted and returned by the spring 31 incorporated therein, the clutch C is maintained in the disengaged state, and pressure oil is supplied through the oil passage c formed inside the fifth shaft 26. As a result, the piston 32 is displaced against the spring 31 and is switched to the clutch engaged state.

One end of the fifth shaft 26 is supported by a side cover 33 attached to the right side surface of the transmission case 9, and the side cover 33 is provided with a multi-plate type braking mechanism B for controlling pivoting. Is equipped. The braking mechanism B is configured such that the ring-shaped piston 34 advances toward the inside of the case by the application of oil pressure, and displaces the pressing plate 35 against the internal spring 36 to thereby displace the fifth shaft 26.
The frictional braking action is added to the pressure plate, the application of the hydraulic pressure is released, and the pressing plate 35 is returned and retracted by the internal spring 36, so that the braking is released. It is incorporated in a hydraulic block 37 attached to the side.

FIG. 11 shows the side clutches 20L, 2L.
A hydraulic circuit diagram and a control system diagram for steering for operating the 0R, the clutch C, and the braking mechanism B are shown. In the figure, V1 is a steering switching valve for selectively shifting the side clutch gears 23L, 23R of the side clutches 20L, 20R, and is neutralized by a solenoid SL1 disposed outside the transmission case 9; And, three positions of the forward and reverse are selected. V2 is a mode switching valve for selectively supplying pressure oil to either the clutch C or the braking mechanism B to switch the turning mode, and is normally energized to a pressure oil supply position to the clutch C and is operated by a solenoid SL2. The position can be switched to the pressure oil supply position to the braking mechanism B.

Further, V3 in FIG.
The operating pressure is a pressure that shifts the side clutch gears 23L and 23R of the side clutches 20L and 20R to the clutch disengagement position and balances them with the spring 24. Is set. A variable relief valve V4 is connected to the lower side of the sequence valve V3, communicates with a transmission case 9 also serving as a hydraulic oil tank, and an oil passage branched from between the sequence valve V3 and the variable relief valve V4. e
Is connected to the primary side of the mode switching valve V2.

The solenoid SL1 for operating the steering switching valve V1 and the solenoid SL2 for operating the mode switching valve V2 are connected to a steering lever 42 as a steering operation tool provided on the handle tower 41 of the control unit 7.
The variable relief valve V4 is mechanically linked to a steering lever 42 while being electrically linked via a control device 43.

As shown in FIGS. 12 and 13, a support shaft 45 is mounted through a bracket 44 attached to the upper right side (as viewed from the driver) of the handle tower 41 so as to be capable of guiding rotation about a fulcrum x in the front-rear direction. In addition, the steering lever 42 is attached to a fulcrum fitting 46 continuously provided at the rear end of the support shaft 45 so as to be swingable about a lateral fulcrum y, and the steering lever 42 is configured to be able to swing crosswise. And
From the fulcrum fitting 46, a first bar is formed by bending a bar into an L shape.
An operation arm 47 is protruded, and a second operation arm 48 made of a plate is protruded from near the front end of the support shaft 45. The first operation arm 47 is connected to a potentiometer 49 attached to the handle tower 41 as follows. Linked like
The operation position of the steering lever 42 is electrically detected.

That is, the operating lever 49a of the potentiometer 49 is urged to rotate clockwise in FIG. 12 by a built-in spring so as to always contact the first operating arm 47 from the side. Operation arm 47 is neutral
The operation lever 49a rotates following the first operation arm 47 while maintaining the contact state regardless of whether the operation is performed in the left or right direction, so that the operation position of the steering lever 42 changes as the output of the potentiometer 49 changes. The detection is continuously performed, and the detection signal is input to the control device 43.

The second operation arm 48 is linked to a release wire 50 for operating the variable relief valve V4 as follows. That is, on the support shaft 45,
A pair of operation arms 51 and 52 are loosely fitted, and both operation arms 51 and 52 are urged to swing toward each other by a torsion spring 53 so as to abut a fixing pin 54 provided on the bracket 44. Supported. A release wire 50 is attached to the free end of one operating arm 51.
The end of the outer wire 50a is connected and supported, and the other end of the operating arm 52 is connected and supported by the end of the inner wire 50b of the release wire 50. The operating pin 48a provided at the free end of the second operating arm 48, which is pivoted around the fulcrum x by the steering lever 42, is connected to both operating arms 51,5.
It is installed between the two.

According to the above configuration, for example, in FIG. 12, when the steering lever 42 is swung from the neutral position n to the right turning direction (leftward in the drawing), the second operation arm 48 is operated.
Is pivoted counterclockwise in the figure, and the operating pin 48a contacts and pivots one operating arm 51 counterclockwise. At this time, since the other operation arm 52 is prevented from swinging counterclockwise by contact with the fixing pin 54, the inner wire 50b of the release wire 50 is relatively pulled out from the outer wire 50a. Conversely, when the steering lever 42 is pivoted from the neutral position n to the left turning direction (rightward in the figure), the second operation arm 48 is pivoted clockwise in the figure, and the operation pin 48a is moved to the other operation arm. The contact 52 is swung clockwise. At this time, one operating arm 5
Since 1 is prevented from swinging clockwise by contact with the fixing pin 54, the inner wire 50b of the release wire 50 is pulled out from the outer wire 50a. That is, even if the steering lever 42 is swung from the neutral position n to the left turning direction or the right turning direction, the inner wire 50b of the release wire 50 is pulled out in accordance with the operation amount, and the wire drawing amount is large. It is linked so that the operating pressure of the variable relief valve V4 becomes higher as much as possible.

The steering switching valve V1 and the sequence valve V3 are incorporated in the hydraulic block 37, and the mode switching valve V2 and the variable relief valve V4 are incorporated in the side cover 33. The hydraulic circuit shown in FIG. 11 is formed by being connected to each other via an oil passage formed in the hydraulic circuit. The steering switching valve V1, the mode switching valve V2, and
The operation structure of the variable relief valve V4 will be described in detail with reference to FIGS.

As shown in FIGS. 14 to 16, the steering switching valve V1 swings a spool 61 mounted on the upper part of a hydraulic block 37 so as to be slidable in the front-rear direction from outside via a support shaft 62. The solenoid SL1 is linked to a lever 64 mounted on the outer end of a support shaft 62.

According to the above configuration, the steering lever 4
2 is in the neutral state n, the solenoid SL1 is in the non-energized state, the spool 61 is held neutral by the return spring 65, and the pressure oil supplied from the pump port P passes through the drain passage D through the transmission case D. It is returned to 9. When the steering lever 42 is operated in the left turning direction, this is detected by the potentiometer 49, the solenoid SL1 is pushed and driven, and the spool 61 is slid leftward in FIG. Is supplied to the left-turn side clutch 20L via the oil passage a.
When the steering lever 42 is operated in the right turning direction, this is detected by the potentiometer 49, the solenoid SL1 is pulled, and the spool 61 is slid to the right in FIG. The pressurized oil is turned to the right side clutch 20R via the oil passage b.
It is supplied to.

As shown in FIGS. 4 and 17, the mode switching valve V 2 is provided with a spool 66 slidably mounted on the upper portion of the side cover 33 in the front-rear direction via a support shaft 67. The operation shaft 68 is configured to be contacted and pressed to perform a sliding operation against a spring 69.
7 is attached to the lever 70 attached to the outer end of the solenoid SL2.
Are linked together.

According to this configuration, when the solenoid SL2 is in the non-energized state, the spool 66 is at the position shown in FIG. 17, and the lower oil passage e of the sequence valve V3 communicates with the oil passage c reaching the clutch C. Have been. When the solenoid SL2 is energized and pulled, the lever 70 is pulled.
Is pivoted counterclockwise in the figure, and the spool 66 is
The oil passage e is communicated with an oil passage f reaching the braking mechanism B.

As shown in FIG. 17, the variable relief valve V4 has a poppet 71 incorporated in the upper part of the side cover 33 so as to be movable in the front-rear direction. A spring 73 for blocking communication of the oil passage e with the drain passage D, and a spring receiving member 74 for supporting a rear end of the spring 73. The spring receiving member 74 is attached to the support shaft 67. The relief pressure can be adjusted by abuttingly pressing and slidingly displacing the operation arm 76 which is pivoted from the outside via a fitted cylindrical support shaft 75, and The inner wire 50 of the release wire 50 is attached to a lever 77 attached to the outer end of the
b is interlockingly connected. The lever 77 is oscillated and biased by a torsion spring 78 in a direction to separate the operation arm 76 from the spring receiving member 74. As shown in FIG. At this time, the relief pressure of the variable relief valve V4 is almost zero. As described above, when the steering lever 42 is swung left and right and the inner wire 50b of the release wire 50 is pulled, the operation arm 76 is swung counterclockwise in FIG. The relief pressure of the variable relief valve V4 gradually increases as the member 74 is pushed in and displaced, and the swing amount of the steering lever 42 increases and the wire pulling amount increases.

The vertical movement of the steering lever 42 which can be operated in a cross direction causes the cutting pre-processing unit 3 to move up and down. That is, FIG.
As shown in FIG. 13, a sensor 81 comprising a potentiometer or a switch for detecting the forward / backward swing of the steering lever 42 and a neutral n in the forward / backward swing direction are provided on the left and right on the extension of the lateral fulcrum y. When the sensor 81 detects that the steering lever 42 has pivoted forward from the neutral position n, the torsion pre-processing unit 3 is moved downward to swing backward. When the movement is detected by the sensor 81, the sensor 81 and a drive elevation mechanism (not shown) of the pre-cutting unit 3 are linked so as to raise the pre-cutting unit 3.

Reference numeral 83 in FIG. 2 denotes a stop and parking brake disposed to act on the end of the third shaft 13, and a pedal 84 provided at the foot of the control unit 7.
As a result, the main clutch (not shown) provided in the transmission system from the engine 6 to the hydrostatic continuously variable transmission 8 is disengaged, and the brake 83 is braked. The parking brake can be applied by locking and holding the pedal 84 at the depressed position.

The steering apparatus according to the present invention is configured as described above, and the steering operation will be described below.

When the steering lever 42 is in the neutral position n, both the side clutches 20L and 20R are in the clutch engaged state, and the left and right crawler traveling devices 1L and 1R
Is driven at a constant speed, and the aircraft runs straight.

When the steering lever 42 is pivoted from neutral n to the right or left, for example, to the right, this is detected by a potentiometer 49 and the solenoid SL1 is energized to drive the steering switching valve V1 to turn right. The position is switched to the position, the pressure oil is supplied via the oil passage b, and the right side clutch 20R is disconnected. In this case, while the steering lever 42 is in the first operating range Rc near the neutral position n, the relief pressure of the relief valve V4 is lower than the operating pressure of the sequence valve V3. 23R is displaced only to the clutch disengagement position, the right crawler traveling device 1R enters the idle state, and the machine body slowly turns rightward by the drive of only the left crawler traveling device 1L.

When the steering lever 42 is in the first operation range Rc
, The relief pressure of the leaf valve V4 becomes greater than the operating pressure of the sequence valve V3, so that the side clutch gear 23R
Is largely displaced beyond the clutch disengagement position, and is engaged with the steering side gear 25R as shown in FIG. In this case, while the steering lever 42 is in the second operation range Rs, the solenoid SL2 is in a non-energized state, and the pressure oil passing through the sequence valve V3 can be supplied to the clutch C. The hydraulic pressure applied to C is limited by the relief valve V4. Therefore, as the steering lever 42 in the second operation range Rs is closer to the neutral n side, the hydraulic pressure applied to the clutch C is lower, the torque transmitted via the clutch C is smaller, and the right crawler traveling device 1R is It is driven at a lower speed and with a smaller torque than the crawler traveling device 1L. The hydraulic pressure applied to the clutch C increases as the steering lever 42 in the second operation range Rs moves away from the neutral position n, and the torque transmitted to the right crawler traveling device 1R via the clutch C gradually increases. Eventually, the clutch C is completely engaged, and the right crawler traveling device 1R is driven in a low speed state decelerated at a predetermined ratio, and the right and left crawler traveling 1R, 1L is driven.
The aircraft gradually turns rightward based on the difference in the driving speeds.

When the steering lever 42 is in the second operation range Rs
, The operation is detected by the potentiometer 49, the solenoid SL2 is energized and driven, the mode switching valve V2 is switched, and the oil passage e is connected to the oil passage f and the hydraulic oil is connected. Is supplied to the braking mechanism B, the oil passage c is communicated with the drain passage D, and the clutch C is disengaged. In this case, since the relief pressure has already been increased by the large operation of the steering lever 42, the fifth shaft 26 is braked by the braking mechanism B, and In a state where the braking of the crawler traveling device 1R is stopped, only the left crawler traveling device 1L is driven, and the aircraft turns sharply (right turn) in the right direction.

Needless to say, the left side clutch 20L is also operated in the first operation range Lc when the steering lever 42 is operated in the left turning direction.
A gentle left turn is performed with only the second operating area L
In s, the left turn is performed by decelerating the left crawler traveling device 1L by engaging the clutch C and performing the third turn.
In the operation range Lb, a sharp left turn is performed while braking the left crawler traveling device 1L.

Here, as shown in FIG. 12, the first operation areas Lc and Rc, the second operation areas Ls and Rs, and the third
The size of the operation areas Lb and Rb is the smallest in the first operation areas Lc and Rc in which the side clutch on the inside of the turn is disengaged and the crawler travel device on the outside of the turn is turned only by the thrust, and the braking of the crawler travel device on the inside of the turn is stopped. The third operation range Lb, Rb in which the turning is performed only by the thrust of the crawler traveling device on the outer side of rotation is the next smallest, and the most operation frequency of turning on the crawler traveling device on the inner side of the turning that is decelerated and the outer crawler traveling device that is not decelerated. The second operation areas Ls and Rs having the highest values are set to be the largest.

The steering device includes a steering lever 42
The left and right are operated to perform the turning mode in which the above three turning states are sequentially displayed. However, the allocation of the operation area of the steering lever 42 can be changed and adjusted. I have.

That is, as shown in FIG. 11, the control device 43 includes a variable resistor VR as an operation range adjusting means.
Is connected, and the boundary position z between the second operation areas Ls, Rs and the third operation areas Lb, Rb can be changed and adjusted by operating the variable resistor VR.

For example, when the variable resistor VR is adjusted to the gentle turning side, the boundary position z is shifted outward, and the second operation range L
s and Rs are enlarged (the third operation areas Lb and Rb are reduced),
At the adjustment limit, the third operation ranges Lb and Rb substantially disappear, and the steering by operating the clutch C is performed even if the steering lever 42 is operated to the maximum. vice versa,
When the variable resistor VR is adjusted to the sharp turning side, the boundary position z is shifted inward, and the second operation ranges Ls and Rs are reduced (third operation range).
The operating ranges Lb and Rb are enlarged), and the
The operation areas Lb and Rb substantially disappear, and the first operation area L
As soon as c and Rc are exceeded, the steering by operating the braking mechanism B is performed. However, in this case, when the operation amount of the steering lever 42 is small, the pressure of the oil passage e is also small. Therefore, when the braking mechanism B is operated with a small steering operation amount, the hydraulic pressure applied to the braking mechanism B is also low. Therefore, the braking force is small, and the braking force increases as the steering operation amount increases.

As shown in FIG. 12, a pair of left and right switches SL and SR are provided as finger operation tools at the upper end of the grip portion 42a of the steering lever 42, and the steering lever 42 is in the neutral position n. When one of the switches SL and SR is pushed, the steering switching valve V1 is switched, and loose steering is performed by disengaging one of the side clutches 20L and 20R. . If the steering lever 42 is out of the neutral position n, the command by the switches SL and SR is ignored.

The present invention can be implemented in the following modes.

(1) As shown in FIG. 18, a potentiometer 49 for detecting the operating position of the steering lever 42
Is calculated by differentiating the detected value of the steering lever 42 to calculate the operation speed of the steering lever 42. When the operation speed of the steering lever 42 is low, the boundary position z is shifted outward and the second operation range Ls , Rs (third operation area L
b, Rb are reduced), and conversely, when the operating speed of the steering lever 42 is high, the boundary position z is shifted inward to expand the third operation areas Ls, Rs (the third operation areas Lb, Rb).
The control device 43 may be configured so that b is reduced). According to this, when the steering operation speed is slow, it is considered that a gentle body steering is going to be performed, and the boundary position is automatically changed so as to widen the operation range of the gentle turning characteristic, and the steering lever 42 is slightly moved. Even with a large operation, steering with a gentle turning characteristic is executed. Also, when the steering operation speed is fast, it is considered that a sharp aircraft steering is going to be performed, and the boundary position is automatically changed so as to widen the operation range of the tight turning characteristic, and the steering lever 42 is operated greatly. Even if it is not, steering with a tight turning characteristic is executed.

(2) The operation area adjusting means not only changes and adjusts the boundary position z between the second operation areas Ls, Rs and the third operation areas Lb, Rb, but also controls the first operation areas Lc, Rc and the second operation areas Lc, Rc. The boundary position w between the operation areas Ls and Rs may be separately changed and adjusted.

(3) Instead of the steering lever 42, a rotating steering wheel can be used as a steering operation tool.

[Brief description of the drawings]

FIG. 1 is a right side view of the entire combine.

FIG. 2 is a front view showing the transmission structure of the traveling transmission case.

FIG. 3 is a longitudinal sectional front view showing an upper half portion of a transmission case.

FIG. 4 is a longitudinal sectional front view showing a lower half of a transmission case.

FIG. 5 is a side view showing the operation structure of the auxiliary transmission mechanism.

FIG. 6 is a vertical sectional front view of a shifter for operating a subtransmission mechanism.

FIG. 7 is a longitudinal sectional front view of a main part showing a state where the sub transmission mechanism is switched to a low speed.

FIG. 8 is a longitudinal sectional front view of a main part showing a state where the sub-transmission mechanism is switched to a medium speed.

FIG. 9 is a longitudinal sectional front view of a main part showing a state where the auxiliary transmission mechanism is switched to a neutral position;

FIG. 10 is a longitudinal sectional front view of a main part showing a state in which the subtransmission mechanism is switched at a high speed.

FIG. 11 is a configuration diagram of a steering hydraulic circuit and a control system.

FIG. 12 is a front view of a steering operation unit.

FIG. 13 is a side view of the steering operation unit.

FIG. 14 is a side view showing a steering control unit.

FIG. 15 is a longitudinal side view showing the periphery of a steering switching valve.

FIG. 16 is a front view showing an operation unit of the steering switching valve.

FIG. 17 is a longitudinal side view showing the periphery of a mode switching valve and a variable relief valve.

FIG. 18 is a configuration diagram showing another embodiment of a steering hydraulic circuit and a control system.

[Explanation of symbols]

 1L, 1R Traveling device 20L, 20R Side clutch 42 Steering operation tool 42a Grip portion 47 Operating member n Neutral z Boundary position Lc, Rc First operation region Ls, Rs Second operation region Lb, Rb Third operation region SL, SR Finger Operation tool

Continued on the front page (72) Inventor Minoru Hiraoka 64 Ishizukita-cho, Sakai City, Osaka Prefecture, in Kubota Sakai Works, Ltd. 72) Inventor Akira Okuyama 64 Ishizu-Kitacho, Sakai City, Osaka Prefecture F-term in Kubota Sakai Works (Reference) 2B043 AA04 AB08 AB11 BA02 BA05 BB14 DA05 DA13 DB05 DB18 EA02 EB01 EB14 ED12 2B076 AA03 DA03 DA15 DB06 DC01 DD02 3D052 AA05 AA16 BB08 BB09 DD03 DD04 EE01 FF01 GG03 GG04 HH01 HH02 HH03 JJ02 JJ12 JJ21 JJ22 JJ25 JJ26 JJ31 JJ37

Claims (5)

[Claims] 1. A crawler-type traveling device comprising a pair of left and right crawler-type traveling devices, each of which is provided with a single steering operation tool in each operation area in a left-right turning direction from a neutral position, so that a turning function becomes higher as the distance from the neutral position increases. A steering device for a farm work machine, comprising: a steering device for an agricultural work machine having the above-mentioned operation region, wherein operation region adjusting means for changing and adjusting the boundary positions of the plurality of operation regions is provided. 2. The method according to claim 1, wherein the plurality of operation areas include a first operation area and a second operation area.
An operation area and a third operation area, wherein the first operation area disengages one of the side clutches provided in each of the transmission systems of the left and right traveling devices to perform gentle turning by one drive. The second operation region is a region where the one traveling device with the side clutch disengaged is decelerated and driven in the same direction as the other traveling device without the side clutch disengaged to perform gentle turning by both drives. The steering of the agricultural work machine according to claim 1, wherein the third operation range is an operation range in which the one traveling device with the side clutch disengaged is braked to make a sharp turn. apparatus. 3. The steering apparatus for an agricultural work machine according to claim 1, wherein the operation area adjusting means is manually and arbitrarily adjusted. 4. The steering apparatus for an agricultural work machine according to claim 1, wherein the operation range adjusting means automatically performs an adjustment operation based on detection of an operation speed of the steering operation tool. 5. The agricultural work according to claim 1, wherein the steering operation device grip portion is provided with a finger operation device that provides a turning state with a gentle turning characteristic in an operation range closest to neutral. Machine steering device.